Nuprl Lemma : subtype-iff-id-mem-fun

∀[A,B:Type].  uiff(A ⊆r B;λx.x ∈ A ⟶ B)


Proof




Definitions occuring in Statement :  uiff: uiff(P;Q),  subtype_rel: A ⊆r B,  uall: ∀[x:A]. B[x],  member: t ∈ T,  lambda: λx.A[x],  function: x:A ⟶ B[x],  universe: Type
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  uiff: uiff(P;Q),  and: P ∧ Q,  uimplies: b supposing a,  subtype_rel: A ⊆r B,  prop: ℙ
Lemmas referenced :  equal-wf-base,  subtype_rel_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  independent_pairFormation,  lambdaEquality,  hypothesisEquality,  applyEquality,  hypothesis,  sqequalHypSubstitution,  sqequalRule,  axiomEquality,  equalityTransitivity,  equalitySymmetry,  lemma_by_obid,  isectElimination,  thin,  functionEquality,  baseClosed,  because_Cache,  productElimination,  independent_pairEquality,  isect_memberEquality,  universeEquality

Latex:
\mforall{}[A,B:Type].    uiff(A  \msubseteq{}r  B;\mlambda{}x.x  \mmember{}  A  {}\mrightarrow{}  B)



Date html generated: 2016_05_13-PM-04_14_14
Last ObjectModification: 2016_01_14-PM-07_28_45

Theory : subtype_1


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